Stimuli In Daily Life Research Articles

Typical Absence Seizures Triggered by Photosensitivity

To describe the characteristics of patients with typical absence seizures (TASs), consistently triggered by photosensitivity. Consecutive patients having TAS induced by intermittent photic stimulation were included in the study. All clinical parameters, EEG, and video-EEG data were assessed during the long-term follow-up. Statistical analyses were performed with SPSS 10.0 software. Nine female and two male patients with a mean age at onset of 14 +/- 5.9 years (range, 7-27 years) and with a mean follow-up of 9 +/- 7.56 years had photosensitive TASs. They constituted 7.64% of absence epilepsies and 0.4% of all patients seen in our tertiary center. The seizures were usually subtle and had a reported frequency of 1 to 9 times daily. Seven patients were clinically photosensitive and reported that some of their TASs were induced by photic stimuli in daily life. All patients also had spontaneous TASs, and four of them had generalized tonic-clonic seizures. EEG results did not show any distinctive features when compared with those of other cases with TASs. Remission could not be achieved in five patients with antiepileptic drug treatments, and we always observed relapses after drug discontinuation or dose reduction in the remaining six cases in remission. Spontaneous remission did not occur even in the five patients older than 30 years. TASs triggered by photosensitivity are a rare and heterogeneous clinical condition with a marked female preponderance. It is notable that TASs do not remit in these cases.

Visual stimuli in daily life.

People of all ages, but especially children and adolescents, are increasingly exposed to visual stimuli. Typical environmental stimuli that can trigger epileptic seizures in susceptible persons are televisions (TVs), computers, videogames (VGs), discothèque lights, venetian blinds, striped walls, rolling stairs (escalators), striped clothing, and sunlight reflected from snow or the sea or interrupted by trees during a ride in a car or train. Less common stimuli are rotating helicopter blades, disfunctioning fluorescent lighting, welding lights, etc. New potentially provocative devices turn up now and then unexpectedly. During the last decades especially, displays have become increasingly dominant in many of our daily-life activities. We therefore focus mainly on the characteristics of artificial light and on current and future developments in video displays and videogames. Because VG playing has been shown also to have positive effects, a rating system might be developed for provocativeness to inform consumers about the content. It is important that patients with epilepsy be informed adequately about their possible visual sensitivity.

Alterations of immune functions in barrier disrupted skin by UVB irradiation

Background: While immunologic events elicited by acute barrier disruption or UVB irradiation have been studied in detail, the biological sequel of multiple insults to the skin is not well understood. Objective: Since the skin would receive a variety of simultaneous stimuli in daily life, we tested the effects of sequential treatments with barrier disruption and UVB exposure on skin immunity. Methods: Earlobes of BALB/c mice received tape-stripping and subsequently low-dose UVB exposure. Control mice were treated with either tape-stripping or UVB. The expression of surface markers and cytokine production in Langerhans cells and keratinocytes and the elicitation response of contact hypersensitivity were compared. Results: By flow cytometry, tape-stripping augmented the expression of MHC class II, CD54, CD80, CD86 and CD40 on Langerhans cells, whereas UVB decreased the expression of some of these molecules. Combination of tape-stripping and UVB induced largely intermediate levels between these two. Upon stimulation with L cells expressing CD40L, Langerhans cells from tape-stripped and UVB-irradiated earlobes strongly transcribed mRNA for interleukin-1β compared to each treatment. In keratinocytes, tape-stripping or UVB slightly upregulated tumor necrosis factor-α and interleukin-1α production at both mRNA and protein levels, whereas these two treatments synergistically increased the production of these cytokines. The in vitro hapten-presenting ability of Langerhans cells to trinitrophenyl-immune lymph node T cells ranked first in tape-stripping, second in tape-stripping plus UVB and third in UVB, and so did the intensity of elicitation responses in contact hypersensitivity to a hapten, picryl chloride. Conclusion: It is suggested that barrier disruption and UVB antagonize with each other in contact hypersensitivity as a reflection of their effects on Langerhans cell antigen-presenting function, but they synergize in cytokine production by both Langerhans cells and keratinocytes.